In my world, this species can only remember what has happened in the last 24 hours (let's assume that the 24 hour period goes from 12:00 AM to 12:00 PM.) For example, if one member of the species kills another member of the species, the rest of the species will remember who the killer is the next day, but not that they actually killed someone. The murder would go unclaimed, as perhaps a freak accident.

They will always remember basic information, such as their name, their identity, their age, and the identities of those around them. They are also capable of learning and remembering activities that cannot be forgotten in normal humans, like riding a bike, writing, or counting. (I don't remember the exact name for these types of activities though.)

Given all this and a planet identical to Earth, would it be possible for this species to build a modern civilization similar to that of modern humans today?

  • $\begingroup$ Normal humans also cannot forget everything that happened more than 24 hours ago. There are plenty of people who forget their identity, or various parts of their past. But things like counting and reading and writing would seem to fall into the learned things category you want to be forgotten. $\endgroup$
    – Seeds
    Commented Aug 8, 2016 at 22:51
  • 1
    $\begingroup$ If the individuals had overlaps, in that some of their group had memories ending at different times, they might evolve to a point that the ones with memories about to expire would pass some of what they had learned to others whose memory was just coming on line. $\endgroup$ Commented Aug 8, 2016 at 23:45
  • $\begingroup$ What do you mean in your first paragraph? How can you "remember" that someone is a killer without knowing that they killed someone (and thus knowing who they killed)? $\endgroup$
    – Aify
    Commented Aug 9, 2016 at 1:51
  • $\begingroup$ @Aify Let me clarify. They know how the killer's name, age, identity, etc, but they don't actually remember that this person was the one who killed people. $\endgroup$
    – fi12
    Commented Aug 9, 2016 at 2:36
  • 2
    $\begingroup$ @Aify - I understood that point to be they would remember people, in general, but not their actions on a specific day. So if someone knew X, they would (when they saw X) remember who this is - but not that they had killed Y even if it happened right in front of them (they would remember who Y was, and 'find out' he's dead, but not remember what happened). Although knowing "what they're like" might get shifted over time depending on what they do, depending on how that memory is stored. $\endgroup$
    – Megha
    Commented Aug 9, 2016 at 19:49

2 Answers 2



Progress would be exceedingly slow, but your people can somehow remember skills like reading and writing, which can serve as a sort of substitute memory once they develop it. They would probably have to be obsessive at noting things down, or else spend a lot of time - a lot more extra time going over the same ground day after day because they forgot they had already done it. And they would lose the thinking time - noting down ideas will help, but following a train of thought would be difficult over time with only written records, and not time to let ideas "stew" inside the mind to synthesize.

On the other hand, learning actual skills is the only way for this people to advance themselves, they can't lean on rote memorization (as our education systems sometimes do) - so perhaps they will get the most out of their education, when they can get it, instead of memorize-and-forgetting it. they would have to learn mathematical formulas, instead of memorizing constants, and learn critical thinking and analysis, instead of memorizing facts and 'standard' interpretations. The line between "learnable skill" and "personal memory" is going to be really, really important to what they can learn, and what they forget.

But, given that they might end up being obsessive over memory, possibly their technology would revolve around overcoming this handicap - which could let them reach an advanced civilization anyway. (similarly, perhaps, to the way so much of our technology revolves around our lack of physical weaponry, so we're always searching for ways to be more and more lethal). This civilization would evolve writing, drawing, and storing records to the most efficient levels. The development of photographs and video would also be prized, and encouraged to develop early and deeply to serve as a prosthetic memory.

Their cave drawings, rather than being symbolic or religious (or historical) would have crude maps to the best places, and a cruder tallying of how often they go to any place, so they know what's picked over, and what's still likely to have food. They would use tokens, maybe, to show what had been done or said or decided on any day, that needed to be acted on the next (like who did which chore, who slacked off, who needed punished). They would develop writing, and ways of preserving their records, as elaborately as they could - because it is instant value, and the more information they can pack in there the better.

It's still a pretty big handicap to overcome, though.


I fail to see how they would even develop language or mathematics at all. Medicine, and many other disciplines, have their roots in verbal tradition; writing was a pretty recent development, paper even more so.

Surely, if it were developed beforehand, and the tech to preserve it was available, one could postulate people being able to learn a language, or math, but if they cannot learn anything else, why would they be able to learn those things?

A good grounding in mathematics, and the ability to develop it further, is the basis of most of the technology we have, and language is key to communicating ideas.

No I don't see a 24 hour memory as workable.


You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .